Evaluation of potting media for marigold under salinity stress condition

Salinity is a major environmental factor limiting agricultural production in the arid and semi-arid regions of the world. Capillary barrier (CB) created from substrate structuring is a technique that can potentially be used to mitigate salinity, however, little has been done to evaluate the use of structured potting media for this purpose. This study evaluated the effects of CB structured potting media on the growth and physiology of marigold under salinity stress. These configurations used the following substrates: vermiculite (V), perlite (P), sand (S), and peat moss (PM) that were stacked in a pot in three layers from top to bottom: V-P-V, V-S-V, and V-P-PM. Four salinity levels of irrigation water were applied to each of the three configurations that included (Control (Desalinated, ECi ≈ 0.6 dS m-1), 3 dS m-1, 6 dS m-1, and 9 dS m-1). The results showed that salinity adversely affects the vegetative, reproductive and physiological parameters of marigold. However, the best growth of marigolds was for those grown in the layered V-S-V media. The layered V-S-V media was the best media among the tested media that can mitigate salinity stress of marigold. The outcome from this study is important for farmers and nursery growers in many arid areas where saline water is the only available irrigation source.